Ok, the time has come for us to do the skin texture. The apple's texture is quite subtle and is totally random and, there is LOADS of it! How on earth do you paint something like that ? Seems like Metacreation forgot to include the 'Apple skin' filter! No really, Like I said in Lesson No. 1; If you want something done start painting !

The apple texture is most obvious with its yellow/bright spots on the left side of the apple in our photo. Select the Airbrush Size: 6, Opacity: 40%, Grain: 20%. And a color of HSV:0,0,85% (RGB:218,218,218).

Draw the texture on the left side of the apple and to the area around branch.
And... you're excused if you don't get it right :-)

Notice in the apple photo that the pattern bends/curves to follow the form of the apple. Of course it does - you think, but try to think of it when painting. If you ignore the form of the apple when painting the texture, the illusion of a round apple will be lost.

I think that texture looks OK. It lacks some of the sharpness of the apple photo, but we can fix some of that with the Dodge tool. Select the Dodge tool: Size: 6, Opacity: 3%. Grain: 100%. Paint extra brightness to the texture of your apple where needed. I added some to the left part of the apple (difficult area I think). And don't forget those small white dots that's covers the apple. I used the Dodge tool for this too. Settings: Size: 3, Opacity: 3%. Grain: 100%.

The finished apple painting (Click on the image for a full resolution).

[Tip] You can add color to grayscale images in Photoshop. See my colorized apple in the summary.